The load beams of disk drive head suspensions often include rails to stiffen the rigid regions of the suspensions. Rails of these types can take any of a wide variety of configurations, and are disclosed generally in the following U.S. patents and publications, all of which are incorporated herein by reference.
InventorU.S. Pat. No./Publication No.Aoyagi et al.4,996,616Khan et al5,877,923Narayan et al.6,697,226Smith et al.6,751,065Peterson et al.5,999,372Bhattacharya et al2003/0231431Takikawa et al.2006/0260118
FIG. 4 is a cross sectional illustration of a prior art load beam rail having a full partial etch thickness. The reduced thickness rail extends along the full length of the load beam and has lower mass than a full thickness rail, thereby enhancing the shock performance of the load beam. Unfortunately, rails of this type exhibit resonance frequency mode sensitivity (e.g., 1st bending mode) to rail thickness variations due to partial etching process variations. Prior art rails having partial etched channels with full thickness tips along the length of the load beam, as shown in the cross sectional illustration of FIG. 5, have reduced sensitivity to this rail thickness variation. However, the extra mass of the full thickness tip can have a negative impact on shock performance.
There remains, a continuing need for improved load beam rail structures. In particular, there is a need for load beams that provide high shock level performance. A load beam providing high shock level performance and high resonance performance (e.g., resistance to mechanical bending in the first bending mode) would be especially desirable. The performance characteristics of the load beam will preferably be insensitive to manufacturing process variability. To be commercially viable the load beam should be capable of being efficiently manufactured.